Johnson & Johnson has acquired a fledgling drug discovery startup built on an antibody with startling anticoagulant properties that could radically reduce the rates of strokes and heart attacks was discovered by chance at a Cambridge hospital.

XO1 Limited launched less than two years ago with the plan to develop a single therapy based on the new anti-thrombin antibody ichorcumab, discovered after the blood of a woman with a head injury in a Cambridge A&E department was found to exhibit unique anticoagulant behaviour, the blood thinned, but the bleeding halted naturally.

Ichorcumab has been developed to mimic the activity of this human antibody which appears to produce an anticoagulated state without predisposition to bleeding. Such a therapy has the potential to greatly reduce the risk of heart attacks and strokes, which are caused by clots to blood vessels, as all anticoagulants developed to date also increase the risk of bleeding, which can prove fatal – a safe anticoagulant without the bleeding would be transformative and a potentially huge blockbuster drug.

It is this technology that J&J subsidiary, Janssen Pharmaceuticals, is acquiring for an undisclosed sum less than two years after XO1 launched, backed by $11 million from Index Ventures with further support from Cambridge Enterprise, the commercialisation division at the university, which held a stake of around 15 per cent in the company.

Peter DiBattiste, head of Global Development, Cardiovascular, at Janssen Research & Development, said Ichorcumab would complement its existing cardiovascular portfolio. “Given Janssen’s leadership in the fields of anticoagulation and biologics, we are well positioned to explore the potential of this next generation anticoagulant,” said DiBattiste.

XO1 was set up as a privately held asset-centric virtual company, which meant its work was almost entirely sub-contracted, allowing it to keep its workforce and overheads to a minimum.